Variable speed constant power fluid transmission



April 19, 1960 E. E. WAGNER 2,932,949

VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION Original Filed Aug. 24. 1955 7 Sheets-Sheet l Apnl 19, 1960 E. E. WAGNER 2,932,949

VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION Original Filed Aug. 24. 1955 7 Sheets-Sheet 2 April 19, 1960 E. E. WAGNER VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION 7 Sheets-Sheet 3 Original Filed Aug. 24. 1955 April 19, 1960 E. E. WAGNER VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION 7 Sheets-Sheet 4 Original Filed Aug. 24. 1955 a m. .7 I

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April 19, 1960 E. E. WAGNER 2,932,949

VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION Original Filed Aug. 24. 1955 7 Sheets-Sheet 5 April 19, 1960 E. E. WAGNER VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION 7 Sheets-Sheet 6 Original Filed Aug. 24. 1955 April 1960 E. E. WAGNER 2,932,949

VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION Original Filed Aug. 24. 1955 7 Sheets-Sheet 7 6 54 [5'6 5! J/ .52 a 0 65' L7.

nited States Patent VARIABLE SPEED CONSTANT POWER FLUID TRANSMISSION Ernest E. Wagner, Santa Ana, Calif.

Original application August 24, 1955', Serial No. 530,397. Divided and this application April 25, 1956, Serial No. 580,665

8 Claims. in. 60-53) This is .a division from my 530,307 filed August 24, 1955.

This invention relates to improvements in fluid transmissions in which a constant speed input shaft, a variable application Serial No.

speedoutput shaft and means for converting the input to prevent imbalance at high rotative speeds and wear induced by large centrifugal forces.

A further and important object of the invention is to provide a variable speed transmission in which the flow of fluid through the various units comprising the device is proportional to the difference in speed between the input and output shafts and thereby circulate fluid through the units at a rate of flow progressively increasing until the minimum or maximum speed is reached, which circulation is intended to keep the units cool and prevent the formation of hot spots and attendant troubles.

Another object of the invention is to provide, in a transmission of this type, a means for conducting fluid flow to one or more devices and returning it in a continuous circuit, one of the devices being adapted to regulate the speedand feed energy back into the unit, which would otherwise be wasted.

A further object of the invention is to provide a device of the character referred to which is of great simplicity, ease of manufacture, assembly and replacement of worn parts.

Other objects and advantages will become apparent from the following description in connection with the accompanying drawings in which Fig. 1 is a cross section of a variable speed unit and its housing on line 1-l of Fig. 2.

Fig. 2 is a cross section on line 2-2 of Fig. 1 through the outer housing only, in order to show the variable speed unit and accessories in their entirety in position relative to the housing.

Fig. 3 is a longitudinal section through the variable speed unit on line 3-3 of Fig, 5. i

Fig. 4 is a horizontal cross section of the rotary valve on line 4-4 ofFig. 5.

Fig. Sis a vertical cross section of the rotary valve on line 5--5 of Fig.4. V

Fig. .6 is a cross section through the variable speed unit on line 6-6 of Fig. 3.

Fig. 7 is a cross section through the unit online 7.-7 of Fig. 3, housing and drive shaft omitted.

Fig. 8 is a cross section through the unit on line' 8--8 of Fig. 3 after removing rotor and drive shaft.

Fig. 9 is a fragmentary cross section on line 9- -9 of Fig. 8.

Figs. 10a and 10b are partial longitudinal sections of a constant power unit wherein Fig. 102: represents the left hand and Fig. 101) the right hand portion of the unit.

Figs. ll-lla, 12-12:: and l3-13a are schematic representations of a constant power unit in various phases of operation.

A variable speed device of the type shown, Figs. l-9, consisting of an input end 10, an output end 35-the two mounted coaxially so that each is free to rotate independently of the other-and fluid inlet-outlet means 24- and 27, has a fixed displacement per revolution and can displace varying amounts of fluids only by a difference in speed between input and output shafts. At times it may and does perform the function of a hydraulic clutch, but it cannot be so employed when applied to a transmission in the manner set forth in this invention. In the description following, it will therefore be understood that reference to a fixed displacement unit shall signify a type of unit as exemplified by Fig. 3, without regard to the phase in which it may be momentarily operating, whether functioning as a pump, as a motor or as a coupling.

For output shaft speeds equal to input shaft speeds there can be no fluid flow and the fixed displacement unit must act as a coupling.

.For output shaft speeds less than input shaft speeds the fixed displacement unit acts as a pump, delivering a volume of fluid proportional to the difference in speed and at a pressure proportional to the load.

For output shaft speeds greater than input shaft speeds, a volume of fluid, again proportional to the difference inspeed and at a pressure proportional to the load on the output shaft must be delivered to the fixed displacement unit which, thereby, acts as a hydraulic motor.

It should be noted that the volume of fluid under pressure involved at any time is proportional to the difference in the speed of the two shafts.

The use of devices which throttle the flow of fluid under pressure, such as a fiow control valve 36 in Figs. 1 and 2, convert the energy in the fluid to heat which cannot be recovered, nor is torque conversion possible by their use.

Whenever it is objectionable to turn substantial amounts of energy into heat either due to the cost of energy or the expense and inconvenience of dissipating the heat, or wherever a variable speeddrive must generate a greater output torque than input torque, then. the energy in the fluid under pressure being metered off must be recaptured or regained and fed back to the input. No

other approach to the problem will result in a drive with constant power output characteristics, wherein the torque output is inversely proportional to the output speed.

Replacement of the flow control valve 36 in Figs. 1 and 2. by a device capable of feeding the energy back to the input shaft is therefore compulsory and any device acceptable must be able to fulfill the conditions outlined in the foregoing. I

A further and important requirement that the device must fulfill is that it must run at a speed in step with the input shaft,i.e., some fixed ratio between the two must prevail, generally 1:1 but not necessarily so.

A positive displacement, reversible, variable delivery unit is such a device, in fact, it can be shown that with a displacement equal to that of the fixed displacement unit and a speed ratio of 1:1, the unit is capable of varying the speed of the output shaft from zero to twice the input speed, the speed depending solely upon the setting of the stroke'control 71, Figs. 10a, 11a, 12a, and 13a, while simultaneously generating, torque values inversely proportional to) the speed so that torque times speed speed range from zero to 200% in Fig. 12a the center of the ring 71 has been moved to the left of the center of the rotor69 and the direction of rotation is as indicated by the arrow. Under these conditions fluid flow through the variable delivery unit can only be from the top to the bottom, as indicated by the arrows. Pressure is generated in the fixed displacement unit 51 proportional to the load on the output shaft 50 and fluid under the influence of this pressure flows via pipe connections 61-63 to the variable delivery unit, driving the rotor 69 in the direction of the arrow and transferring the power contained in the fluid to the input shaft 55. The variable delivery unit is operating as a motor. Fluid leaving the variable delivery unit via pipe connection 64 is under a minute head only, just enough to get the fluid out of the unit and into the reservoir. Thus the energy contained in the speed regulating volume of fluid coming from the differential unit has, for all practical purposes been fully recovered and fed back to the input shaft, as and in the manner above stated. Inasmuch as the speed reduction is proportional to the volume with drawn and the volume withdrawn is proportional to the amount of movement of the stroke adjustor 71 from neutral, the speed reduction-not the actual output speed-is directly proportional to the stroke adjustor setting.

The torque-no'energy being wasted-is proportional to the reciprocal of the speed, thus true torque conversion is achieved which is tantamount to constant power output.

In Fig. 13a the center of the ring 71 has been moved to the right of the center of the rotor 69 and the direction of rotation is as indicated by the arrow. Under these conditions fluid flow through the variable delivery unit can only be from the bottom to the top, per arrows, that is, fluid is taken in from the reservoir 68 and discharged through pipe connections 63-66-61 to the fixed displacement unit 51, therefore the variable delivery unit is operating as a pump, adding speed to the output shaft .50 in addition to and above the speed of the input shaft .55. The amount of speed added by the variable delivery unit is proportional to the volume added, which volume is proportional to the amount of movement of the stroke adjustor 71 from neutral, but the movement of the stroke adjustor is in a direction opposite to the movement causing a reduction in speed. The increase in speed-not the actual output speed-is directly proportional to the stroke adjustor setting.

At synchronous speed-output speed equaling input speed-all of the power to the input shaft 55 is transferred via the rotor 70 of the fixed displacement unit 51 to the output shaft 50, however, as the stroke adjustor is moved to the right from zero, a greater and greater part of the power input flows via the rotor 69. At no time is any energy wasted by throttling and all of the input power is transferred to the output shaft. As the speed increases the output torque mustdecrease as the reciprocal of the speed in order to maintain constant power output.

From the foregoing description it is, quite evident that the size of the variable delivery unit determines the range of speeds of the output shaft by its ability to add to or subtract from the input speed.

If the displacement of the variable delivery unit per revolution of the input shaft is expressed as a percentage of the displacement of the fixed displacement unit per revolution of the input shaft, then a drive with a 100% variable delivery unit will necessarily have an output of the input speed.

For a drive with a 50% variable delivery unit the output speed range will be from 50% to 150% of the input speed.

A drive equipped with a 150% variable delivery unit will have an output speed range of minus 50% to plus in said diminished end,

output speed of the drive, upon moving the stroke ad justor from zero, will begin to slow down and continue 7 to do so until it reaches zero output speed. Thereafter, if movement of the stroke adjustor is continued in the same direction, the output shaft will reverse and the speed increase until it equals 50% of the input speed. For speeds from 100% to 250% of input speed the stroke adjustor is moved in a direction opposite to the direction of movement for speed reduction, by an amount proportional to the speed increase. 1

The total movement of the stroke adjustor, using zero speed as the starting point of measurement, is directly proportional to the speed for the entire range of operation, forward and reverse.

1 claim as my invention:

1. A variable speed constant power fluid transmission comprising a balanced vane type unit having a rotor and an independently rotatable housing enclosing said rotor to form pumping chambers and provided with passageways, said housing having a diametrically diminished end provided with inlet-outlet passageways and connected with an output shaft, a stationary body co-operating with said end and having an inlet and an outlet for communication with the inlet-outlet passageways of said diminished end to form a rotary valve with said end, a variable delivery reversible pump having a fluid inlet and an outlet, said pump comprising a fixed housing enclosing a rotor to form pumping chambers and provided with passageways communicating with said fluid inlet and outlet, an input shaft coupling together the rotors of said balanced vane type unit and variable delivery pump, a driving means for said input shaft, and fluid passageways connecting the inlet and outlet of said balanced vane type unit with the inlet and outlet of said variable delivery reversible pump.

2. A variable speed constant power fluid transmission comprising a balanced vane type unit having a rotor and an independently rotatable housing enclosing said rotor to form pumping chambers and having inlet-outlet passageways and a diametrically diminished end provided with passageways and terminating in. an "output shaft, a stationary body cooperating with said end to form a rotary valve havingan inlet and an outlet and inlet-outlet passageways for communicating with the passageways a variable delivery reversible pump having a fluid inlet and an outlet and a fixed housing enclosing a rotor to form pumping chambers and provided with passageways communicating with said. fluid inlet and outlet, an input shaft coupling together the rotor of said balanced vane type unit and the rotor of said variable delivery reversible pump and mounting a driving means, and fluid passageways interconnecting the inlet-outlet ports of said balanced vane type unit and said variable displacement unit for transferring the speed regulating fluid volume and the energy contained therein, between said units.

3. A variable speed constant power fluid transmission including a balanced vane type unit having a housing enclosing a rotor to form pumping chambers and rotatable independently of said rotor, said housing having a dia-.

metrically diminished end provided with passageways, and an output shaft'integral therewith, a body cooperating with said diminished end to form a rotary valve having an inlet and an outlet, a variable delivery reversible unit comp-rising a fixed housing having passageways and an inlet and an outlet, said fixed housing encasiug a rotor to form pumping chambers and including means for adjusting the stroke of said unit to vary the speed of said output shaft, an input shaft coupling together the rotor of said balanced vane type unit and the rotor of said variable delivery reversible unit and mounting a driving means for said input shaft, and fluid passageways interconnecting the inlet-outlet ports of said balanced vane 250%. The minus sign indicates reverse speed. Thetype unit and said variable displacement unit.

4. A variable speed constant power fluid transmission comprising a rotatable housing havingfluid-conducti'ng passageways and terminating in a pintle having inlet and outlet ports;- a rotonwithin said housing forming pump chambers therebetweenand in communication with the fluidcondu'cting passageways insaid housing and with tlie'por'ts inf'said pintle -and'consti'tuting with-said housing a fixed displacement unit; anoutput' shaft driven by the pinue of said rotatablehousing-ya stationary valve body surrounding said pintle' and having inlet outlet ports register'ing with the'inle't-outlet ports in said pintle and forming a rotary valve'; a -st ationa'ry housing having inlet-outlet ports; 'a rotor within 'said stationary housing forming pumping chambers therebetween; said stationary housing and rotor defining a variable displacement unit; an input snares driving means mounted thereon; the rotor of said ,fiire d displacemeht unit a'nd -the rotor of said variable displacement unit being connected to said input shaft to run in sy'nchr'onism therewith; and fluid passageways interconnecting said inlet-outlet ports of said fixed and said variable displacement units to transfer the speed regulating fluid volume and the energy contained therein between said units. 7

5. A variable spged constant power fluid transmission comprising a cylii idrical rotatable housing having fluid conducting passageways, a rotor within said housing forming pumping chambers therebetween and defining a fixed displacement unitgsaidhousing connected with an output 'sh'aft';:'a stationary body mounted on and surrounding a reduced portion of said cylindrical rotatable housing and having ports registering with the fluid conducting passageways -in's'aid housing and thereby form a rotary valve, 7

' said stationary body provided with an inlet and an outlet;

an'stationary housing having inlet-outletports, a rotor within said stationary housing forming pumping chambers therebetween and defining a variable displacement unit; an input shaft mountinga driving means "and connecting both said rotors together mechanically; and fluid coni ducting passageways connecting both, said rotors together hydraulically thereby transferring the speed and torque regulating fluidg-betweensaid units.

6. A variable-,speed constant power fluid transmission comprising a rotatable housing encasing a rotor to form pumping chambers therebetween, said rotatable housing having fluid conducting passageways; an output shaft connected to said ro'tatablehousing to be driven thereby; 'a' stationarybodymounted upon and surrounding areduced portionof said housing, said body having ports co-operating'with the passageways in said rotatable housand an outlet; a' stationary housing encasing a rotor to form pumping chambers therebetween, said stationary housing having inlet outlet' passageways communicating withsaid rotor,"an input shaft'upon'which the rotors of said-rotatable and stationary housings are mounted to rotate therewith at the speed of said input shaft, 21 driving means for said input shaft, and fluid passageways interconnecting the inlet-outlet ports ofsaid valve body and said stationary housing for transferring the power con- 1 tained in the-fluid between'said units. 1

7. In a variable speed constant power fluid transmis s-ion; the combination of: a main housing, aninput shaft therein; a drivingm'eans for sa'idj'shaftya fixed displace= ment rotor'connected to said shaft to rotate in synchronism -ther'ewith; a rotatable'm'ember having fluid passageways enclosing said fixed displacement rotorto said rotatable memberterminating in -a -pintle'l1aving' inlet and outlet, ports communicating with the fluid conducting passage form pumping chambers therebetween,

ways therein; an'output shaft adaptedto be driven by said pintle; a stationary valve body surrounding said pintle and having inlet-outlet portsregistering with the inlet-outlet ports in said pintle and co-operating with said pintle to form a rotary valve; a supplemental housing I associated with'said main housingand enclosing a part of said input'shaft;-a variable displacement rotor Within said supplemental housing to form pumping chambers therebetween and having inlet-outlet ports, said variable displacement rotor'connected with said input shaft to runinsynchronism therewith and defining a variable displacement unit; fluid passageways intercounecting the inlet-outlet ports of said stationary valve body with'the' inlet-outletports of said supplemental housing to transfer the speed regulating fluidvolume and the energy contained therein between said units. 7 a

8; A variablespeed constant power fluid transmission, which comprises positive displacement hydraulic driven means having-a rotatable housing and a rotor and a fluid distributor, bearing means to mount said rotor within said rotatable housing't'o'form pumping chambers, additional bearingmeans coaxial-with said'fir'st mentioned'bearing means to -;support said rotatable housing for independent rotation within said distributor, inlet-outlet passage means in said distributorfor conducting fluid to andfrom said rotatable housing and rotor; positive displacement variable delivery reversible flow hydraulic pump means having a lfixed housing with inlet-outlet passage means surrounding a ro't'or to form pumping chambers in "communication with said pump housing passage means; ja rotor shaft to connect said drivenq'means YOKOIZiO said. pump means rotor'for conjoint rotation; means eiiecting rota- 1 tion of said rotor shaft; afcontr'ol manifold; means inter- V ing: to form a rotary valve, said body having an intake connectinghydraulically said distributor passage means, said manifold, and said pump housing-passage'means; and means for "connecting said rotatable housing to an output shaft.

9 References Gited in the file of this patent 

